Meters per Second to Knots Converter | m/s to knot

What this converter does

Scientific data gives wind and currents in metres per second, but the people who sail and fly through them work in knots. This converter takes a speed in m/s and turns it into knots, so a figure from a model or a sensor lands on the scale used at sea and in the air. Enter the m/s value and read off the knots.

Two units for the same wind

There is a neat split here. Metres per second is the unit of science, the one oceanographers and meteorologists use because it fits the physics of how air and water move. Knots is the unit of operation, the one on a ship's instruments, a pilot's airspeed, and the forecasts they both rely on, because it ties straight to the latitude and longitude of a chart. So the same wind can be a number in m/s in a research report and a number in knots on the bridge, and this conversion carries it from one world to the other.

The conversion factor

One metre per second is 1.94384 knots, so:

knots = m/s × 1.94384

The relationship runs through the definition of a knot, which is one nautical mile, 1,852 metres, per hour, and so works out to 0.514444 m/s. Flipping that gives the 1.94384 above. The knot figure comes out close to double the m/s.

A quick estimate

The factor is close to 1.94, just under 2, so for a fast figure, nearly double the m/s value. Take 10 m/s, double is 20, ease off a touch and you are near 19.4, which matches the exact answer. Doubling and trimming slightly is an easy way to move a scientific wind speed onto the knot scale in your head.

A worked example

Say a weather model reports a wind of 15 m/s and you want it in knots to read against a marine forecast.

• 15 × 1.94384 = 29.2 knots

So 15 m/s of wind is about 29 knots, a strong breeze building toward a near-gale, the sort of figure a sailor weighs carefully. Converting it puts the scientific reading on the same scale as the warnings and limits that boats and aircraft actually use.

Common m/s speeds in knots

For a feel, 10 m/s is a little over 19 knots, and 20 m/s comes in near 39 knots.

Questions people ask

How do I convert m/s to knots?

Multiply the speed in m/s by 1.94384. For a quick estimate, nearly double the m/s figure.

Why do science and navigation use different units?

Metres per second fits the physics of moving air and water, so science uses it. Knots ties to latitude and longitude on a chart, so navigation uses it. The wind is the same; only the unit changes.

Why is the knots figure close to double the m/s?

One knot is about 0.514 m/s, so it takes nearly two knots to match one metre per second, which puts the knot figure at roughly twice the m/s.

References

1. National Institute of Standards and Technology (NIST), Special Publication 811, Guide for the Use of the International System of Units (unit conversion factors). https://www.nist.gov/pml/special-publication-811
2. National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, What is the difference between a nautical mile and a knot? https://oceanservice.noaa.gov/facts/nautical-mile-knot.html